Inferring a document's relevance is an important factor when a search engine provides search results in response to a user submitted search query. Typically, search engines find and rank a plurality of online documents based on a document's inferred relevance to the submitted search query. After receiving a search query and identifying documents associated with the query, the search engines then display the most relevant documents near the top of a list of the identified documents.
Accordingly, it is important for search engines to accurately infer document relevance so that a user is presented with a list of online documents that are relevant to a submitted search query.